(Security market line) You are considering the construction of a portfolio comprised of equal imvestments in each of four difforent stocks. The betas for each stock aro found bolow: (Click on the icon O in order fo copy its contents into a spreadsheet.) a. What is the portfolio beta for your proposed investment porttolio? b. How would a 25 percent incroase in the expected return on the market impact the expocted return d your portfolio? c. How would a 25 percent decrease in the expected retum on the market impact the expocted return on each asset? a. The portfolis beta for your proposed invostrnent portfolio is (Pound to three docimal places)